Polymorphisms of the angiotensinogen gene, the endothelial nitric oxide synthase gene, and the interleukin-1β gene promoter in women with idiopathic recurrent miscarriage

Interleukin (IL)-1beta, angiotensinogen (Agt), and endothelium-derived nitric oxide synthase (eNOS) are thought to be involved in idiopathic recurrent miscarriage (IRM). We investigated the correlation between IRM and common polymorphisms in Agt, Nos3 and IL-1beta genes: one polymorphism in the promoter region of the IL-1beta gene, one in exon 2 of the Agt gene, and one in exon 7 of the Nos3 gene. A total of 130 women with a history of IRM and 67 healthy control women were included in the study. Genotyping for the C/T transition at position -511 in the promoter region of IL1B, for the single base M235T polymorphism of Agt, and for the missense Glu298Asp variant of Nos3 was performed using PCR, an allele-specific oligonucleotide hybridization assay, and pyrosequencing, respectively. Allele and genotype frequencies of all polymorphisms were similar among women with IRM and controls. Between women with primary and secondary recurrent miscarriages, no statistically significant differences between allele and genotype frequencies were observed. Despite promising experimental data, our data fall short of showing any significant association between a variant of the promoter region of IL1B, the M235T polymorphism of Agt, and the Glu298Asp missense variant of Nos3 and the occurrence of IRM.